US government approves transgenic chicken

The US Food and Drug Administration (FDA) has approved a chicken genetically engineered to produce a drug in its eggs.

The drug, Kanuma (sebelipase alfa), is a recombinant human enzyme marketed by Alexion Pharmaceuticals. It replaces a faulty enzyme in people with a rare, inherited condition that prevents the body from breaking down fatty molecules within its cells.

With the 8 December FDA approval, Kanuma joins a small group of ‘farmaceuticals’ on the US market. In 2009, the agency approved genetically modified goats that produce an anticoagulant called ATryn in their milk. And last year, the FDA okayed a drug to treat hereditary angioedema that is produced by transgenic rabbits.

The FDA’s latest decision “shows that the ATryn goats weren’t just a one-off,” says Jay Cormier, a lawyer at Hyman, Phelps & McNamara in Washington DC and a former scientific reviewer for the FDA. “The process can function for more than just one particular unique case.” The agency moved quickly to consider Kanuma, giving it a priority review, orphan drug status and a breakthrough therapy designation.

The disease that it is designed to treat, called lysosomal acid lipase deficiency (LAL-D) , causes fat to accumulate in sufferers’ livers, spleens and vasculature. A form of the disease that strikes infants is quickly fatal. A second form that affects older patients causes liver enlargement, fibrosis, and cirrhosis, as well as cardiovascular disease.

“Before we had this drug, we didn’t have any treatment for the patients that really addressed the underlying biochemical defect in the disorder,” says Barbara Burton, a paediatrician with the Northwestern University Feinberg School of Medicine in Chicago, Illinois. Clinicians could only provide nutrition and supportive care to infants, says Burton, who worked with Alexion to conduct the clinical trials. Older patients are treated with statins — which don’t address the fatty buildup in the liver.